This invention relates generally to a tillage implement and more specifically to a shovel for such an implement.
Chisel plows and similar ground tillage implements have utilized a twisted shovel with a substantially flat forwardly facing surface and with forwardly facing upper and lower end portions transversely offset with respect to each other. The soil is raised by the lower portion and ideally follows the forwardly facing surface so that it is turned and falls on top of trash. Generally the upper and lower portions are offset laterally with respect to each other so that as the soil follows the forward surface around the shovel it will be displaced to one side of the groove or furrow being formed by the lower portion of the shovel. Twisted shovels are designed to lift and turn the ground to allow aeration and moisture entry and reduce soil erosion. Turning the soil results in better trash coverage and better mixing which, for example, is advantageous when fertilizer is to be incorporated into the soil.
Typical of previous twisted shovels, the soil often does not follow the forwad surface of the shovel, but instead spills over the sides of the shovel and falls back into the trench or furrow being cut. The inability of the shovels to properly direct the flow of soil is especially evident when moisture conditions are not optimum, for example when the soil is extremely dry. Often the shovel will bulldoze the soil rather than cause it to ribbon about its contour, which results in ineffective mixing and covering. In addition, the generally flat-surfaced twisted shovels often cannot direct trash flow effectively. As trash slides over the edges of the shovel rather than lifting and turning with the contour, it tends to ball up in front of the shank. Because the trash and soil do not lift and turn, coverage and mixing is reduced. Many of the advantages of utilizing the twisted shovel design, including increased trash coverage and mixing as well as better aeration and increased erosion reistance, are lost when the soil and trash do not follow the contour of the shovel.
Another disadvantage of the twisted shovels typical of previous designs is lack of resistance to bending near the portion of the shovekl which engages the soil. To increase the bending strength, shovels have typically been made thicker or wider.